For example, in a display region of the display device, gate lines extend in a row direction (horizontal direction) and are arrayed at a predetermined pitch in a column direction (vertical direction), and data lines extend in the column direction and are arrayed at a predetermined pitch in the row direction. A data signal is supplied from a source driver IC to the data line, and a gate signal is supplied from a gate driver IC to the gate line. Because a pitch of a terminal of the driver IC is smaller than a pitch of a signal line (data line, gate line), a length of the lead line that relays the terminal of the driver IC and the signal line varies depending on a place.
When the length of the lead line varies, an electric resistance from the terminal of the driver IC to the signal line varies depending on the place. Resultantly, a luminance difference is generated in a display region, and display quality is degraded. A prior art discloses a technology of homogenizing a resistance of the lead line by adjusting a width (line width) of the lead line (for example, see Japanese Unexamined Patent Application Publication No. H08-076136).